Method of straightening sheet metal



Apr. 24, 1923.

c. FLINN METHOD OF STRAIGHTENING SHEET METAL Filed May 27, 1920 III! IN VEN TOR A TTORNE Y 8 i atented p igza "onnrsrornna ,rnmn, or MILTON, rEmtstLvaNIA, as'sreivbaro' ammiciivfere AND FOUNDRY COMPANY, or NEW YORK, N. Y., a coaronarron OF NEW JEEsEY.

Application filed may 27, 1920. SeriaI Ho. 334,651.

To all 41271-0721 it may concern: I

Beit knownthat I, CHRISTOPHER FLINN, residing at Milton, Northumberland County, Pennsylvania, and being a citizen of the United States, have invented certain new and useful Improvements in Methods of Straightening Sheet Metal, of which the following isa full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and'to use the same, reference being had to the accompanying drawings, which illustrate the preferred form of the invention, though it is to be understood that the invention is not limited to the exact details of construction shown and described, as it is obvious that various modifications thereoi within the scope of the claims will occur to persons skilled in the art.

In said drawings:

Figure 1 is a view in elevation showing the die blocks with the dies positioned to press the tapered rib in a plate and a plate between the dies with the rib pressed therein; p

Figure 2 is partly central vertical section of Fig. l-and partly an end elevation of the upper die block;

Figure 3 is a view, similar to Fig. 1, showing the dies reversed so as to press out the rib pressed in the plate;

Figure 4: shows a plate before the tapered rib has been pressed in it; with the rib pressed in it; and after the rib has been pressed out;

, Figure 5 is a plan view of a long plate with the tapered ribs pressed in; and

Figure 6 is a a side elevation of the plate shown in Figure 5.

It is an object of my invention to provide a new and improved method of removing the camber from sheet metal plates by pressing a tapered rib across the plate from the inside of the camber so as tostretch that portion of the plate and then to press out the tapered rib leaving the plate. fiat.-

For carrying out my process I have pro-- vided die holding blocks 1 and 2, the rocking die holding block 1 being attached to the top die holding block Sby a pin 4 which passes through an openin in the block 1 and through openings in die lugs 5 on the block 3. The block 3 is adapted to beat tached to the moving head of a punching machine or press while the block'2 is adapted to hold the dies in position in the holding to be mounted onthe base or bed plate of the machine; The die holdingblocks 1 and '55 are provided with openings that receive with the pointed end of the rib on a line with the beginning of the camber in the plate, and the rib extending with the camber to the edge of the plate. 'Pressing the tapered rib in the plate provides for a graduated stretching of the plate that is greatest where the camber is greatest and Y which tapers off to nothing on the line at which the camber begins.

After the tapered rib has been pressed in the plate the plate is removed and the dies are withdrawn, turned to the position shown in Fig. 3 and inserted in the openings in the die holding blocks. The plate is then inserted between the dies and the rib pressed out leaving the platefiat. While in Fig. 4

but one rib has been shown aspressed in the plate, in the case of longer plates two or more ribs can be made, each serving to cor met the camber in a portion of the plate whenpressed out.

In the case of the long plate shown in Figs. 5 and 6, it will be notedthat the edges A- B and UD are slightly curved so that the middle point of a straight line joining the ends of the edge C-D of the plate of I the standard length of 33 feet would be displaced approximately 1 inch from the edge C-D. To correct the camber in the plate as shown, several ribs would have'to be pressed into the plate and then pressed out, some for instance, extendin as shown from the edge 4A1-B to the edge b-D While others would extend from points between the edges to the edge C-D, the number of ribs and the extent to which they extend to the edge C D into the plate depending on the amount of camber to be corrected in the section of plate adjacent to the rib. The distance the point of the rib isfrom theedge C--D is considered as the length of the camber and the line at Which the point of the rib is, is considered as the line of origin of the camber of that section of the plate.

What I claim is:

l. The method of removing the camber from a plate which consists in forming a tapered rib in the plate so as to stretch the plate and then pressing out; the rib.

2. The method of removing the camber from a plate which consists in pressing in the plate a tapered rib of the length of the camber and then pressing out the rib.

3. The method of removing the camber from. a plate which consists in pressing a tapered rib in the plate, the rib being disposed With its pointed end at the line of origin or" the camber and then pressing out the rib. c

4. The method of removing the camber from a plate which consists in pressing 9.

tapered rib in the plate, the rib being disposed With its. pointed end at the line of origin of the camber and extending to the plate edge and then pressing out the rib. 5. The method of removing the camber from a plate which consists in pressing a tapered rib in said plate the rib being disposed with its point of greatest depression at the plate edge, and pressing out said rib.

6. The method of removing the camber from a plate -which consists in pressing a tapered rib in said plate so as to stretch the plate in proportion to the degree of camber and pressing out said rib to leave said plate fiat.

In Witness whereof I have hereunto set my hand inthe presence of two Witnesses. CHRISTOPHER FLINN. Witnesses:

MARY L. GILMARTIN, R. W. Morzn'r'r. 

